At present, University of Wisconsin solution (UW solution) is generally used for brain death liver m transplantation in the US and Europe (Transplant proc, vol. 31, p. 2069-2070, 1999). This is because UW solution enables a longer-term cold ischemic preservation of the liver as compared to other organ preservation solutions. However, since UW solution is extremely highly viscous, the blood in blood vessels needs to be washed away with Ringer's solution etc. having low viscosity, prior to the start of the cold ischemic preservation of the liver. In addition, perfusion with UW solution is time-consuming. Further, UW solution is an intracellular preservation solution (electrolyte is equivalent to intracellular composition) and has a high potassium concentration (125 mM). A high potassium concentration causes contraction of blood vessels, causing long time organ perfusion. What is more, UW solution in the liver needs to be once substituted with Ringer's solution etc. immediately before recanalizing the blood flow after transplantation of the liver into a patient, so that high concentration potassium will not flow into the body of the patient. Moreover, since UW solution contains a chemically-unstable active oxygen scavenger (radical scavenger) as a component, the shelf life thereof is short even when preserved in a cold place, and the unit price is very high.
To solve these disadvantages, the present inventors have developed ET-Kyoto solution and New ET-Kyoto solution, which are extracellular solutions having a completely different composition from that of UW solution and a low potassium concentration, and containing trehalose which is a saccharide that stabilizes cellular membrane and suppresses cell injury (JP-B-3253131, Yonsei Medical Journal, vol. 45, No. 6, p. 1107-1114, 2004). New ET-Kyoto solution has a composition similar to that of ET-Kyoto solution, but is different from ET-Kyoto solution in that it contains dibutyryl cAMP (db-cAMP), nitroglycerin and N-acetylcysteine. It is described that addition of db-cAMP and nitroglycerin to a preservation solution further enhances post-transplant organ function as compared to ET-Kyoto solution (Yonsei Medical Journal, vol. 45, No. 6, p. 1107-1114, 2004).
It has already been demonstrated at the animal experiment level that ET-Kyoto solution exhibits an effect equivalent to that of UW solution used for cold ischemic preservation of the kidney, lung, muscle or skin. However, no detailed report has documented as to the effect on the liver preservation.
In the lung preservation, the New ET-Kyoto solution shows an effect superior to that of UW solution, and has already been introduced into the clinical application and lung transplantation in Kyoto University.
Thus, the development of a liver preservation solution, which is more superior in an action to maintain organ function, and superior in safety, operability and chemical stability, has been desired.
In view of the above-mentioned situation, it is an object of the present invention to provide a liver preservation solution, which is superior in an action to maintain organ function, as well as safety, easiness of use and chemical stability.